Question #2 Answer
Even the very best players in the World successfully roquet at 15 yards less than 50% of the time. How much less the rest of we mortals - especially if the price for missing will be high?!
Therefore, the shots on offer here are NOT as easy as they seem. If you think that (in this example) the chance of an immediate break is less than 50% for you, then probably the best thing to do is to take the shot at Black with Red. If you miss then the pressure is still high for Black, as he knows that Yellow will next go to the A Baulk where partner lies.
If Red hits then there is a great leave here as illustrated, with Red located in a wired position from Black at Yellow's wicket!